bdv.img.cache

Interface CacheArrayLoader<A extends DataAccess>

Type Parameters:

A - type of access to cell data, currently always a VolatileAccess.

All Known Implementing Classes:

CatmaidVolatileIntArrayLoader, ImarisVolatileByteArrayLoader, ImarisVolatileFloatArrayLoader, ImarisVolatileShortArrayLoader, OpenConnectomeVolatileArrayLoader, RemoteVolatileShortArrayLoader

public interface CacheArrayLoader<A extends DataAccess>

Provider of volatile Cell data. This is implemented by data back-ends to the VolatileGlobalCellCache.

Author:

Tobias Pietzsch

Method Summary

Modifier and Type	Method and Description
default int	getBytesPerElement() How many bytes does one element (voxel) occupy? This is used only for statistics, i.e., estimating I/O bandwidth.
default EmptyArrayCreator<A>	getEmptyArrayCreator() Implementing classes must override this if A is not a standard VolatileArrayDataAccess type.
A	loadArray(int timepoint, int setup, int level, int[] dimensions, long[] min) Load cell data into memory.

Method Detail

getBytesPerElement

default int getBytesPerElement()

How many bytes does one element (voxel) occupy? This is used only for statistics, i.e., estimating I/O bandwidth. Implementing classes can return an estimate if element size is varying or unknown.

Returns:

number of bytes required to store one element.

getEmptyArrayCreator

default EmptyArrayCreator<A> getEmptyArrayCreator()

Implementing classes must override this if A is not a standard VolatileArrayDataAccess type. The default implementation returns null, which will let CreateInvalidVolatileCell.get(...) try to figure out the appropriate DefaultEmptyArrayCreator.

Default access types are

• DirtyVolatileByteArray
• VolatileByteArray
• DirtyVolatileCharArray
• VolatileCharArray
• DirtyVolatileDoubleArray
• VolatileDoubleArray
• DirtyVolatileFloatArray
• VolatileFloatArray
• DirtyVolatileIntArray
• VolatileIntArray
• DirtyVolatileLongArray
• VolatileLongArray
• DirtyVolatileShortArray
• VolatileShortArray

Returns:

an EmptyArrayCreator for A or null.

loadArray

A loadArray(int timepoint,
            int setup,
            int level,
            int[] dimensions,
            long[] min)
     throws InterruptedException

Load cell data into memory. This method blocks until data is successfully loaded. If it completes normally, the returned data is always valid. If anything goes wrong, an InterruptedException is thrown.

Parameters specify the image within the data set and the location of the cell within the image: timepoint, setup, and level define the stack, where setup is a combination of angle, channel, etc., and level is the resolution level (for multi-resolution data). dimensions is the size of the block to load (in voxels). min is the starting coordinate of the block in the stack (in voxels).

Usually, the CacheArrayLoader interface is implemented in conjunction with implementing a ViewerImgLoader for a BDV data back-end. You do not need to be able to load blocks of arbitrary sizes and offsets here -- just the ones that you will use from the images returned by your ViewerImgLoader. For an example, look at CatmaidImageLoader. There, the blockDimensions are defined in the constructor, according to the tile size of the data set. These blockDimensions are then used for every image that the CatmaidImageLoader provides. Therefore, all calls to loadArray(int, int, int, int[], long[]) will have predictable dimensions (corresponding to tile size of the data set) and min offsets (multiples of the tile size).

The only exception to this rule is at the (max) border of the stack. The boundary cells may have a truncated shape. For example, if your image size is 20x20x1 and your cell size is 16x16x1, you will have cell sizes
(16x16x1), (4x16x1)
(16x4x1), (4x4x1)

Parameters:

timepoint - the timepoint of the stack.

setup - the setup of the stack.

level - the resolution level of the stack (0 for full resolution).

dimensions - the size of the block to load (in voxels).

min - the min coordinate of the block in the stack (in voxels).

Returns:

loaded cell data.

Throws:

InterruptedException